OS Detection

Enable OS Detection (-O)

Explanation: This enables the OS detection feature to attempt to determine the operating system of the target.

nmap -O <target>

Limit OS Detection to Promising Targets (--osscan-limit)

Explanation: This option restricts OS detection to targets that have at least one open and one closed TCP port, saving time on scans.

nmap -O --osscan-limit <target>

Guess OS Detection Results (--osscan-guess or --fuzzy)

Explanation: If Nmap is unsure about the OS, it will make more aggressive guesses and provide near-matches with confidence levels.

nmap -O --osscan-guess <target>

Set the Maximum Number of OS Detection Tries (--max-os-tries)

Explanation: This option sets the maximum number of attempts Nmap will make when trying to detect the OS. Reducing the number can speed up scans, while increasing it may improve accuracy.

nmap -O --max-os-tries 3 <target>